package com.tanhua.server.interceptor;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.tanhua.server.utils.Cache;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.core.MethodParameter;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.http.MediaType;
import org.springframework.http.server.ServerHttpRequest;
import org.springframework.http.server.ServerHttpResponse;
import org.springframework.http.server.ServletServerHttpRequest;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.servlet.mvc.method.annotation.ResponseBodyAdvice;

import javax.servlet.http.HttpServletRequest;
import java.util.concurrent.TimeUnit;

@ControllerAdvice
public class MyResponseBodyAdvice implements ResponseBodyAdvice {
    @Value("${tanhua.cache.enable}")
    private Boolean enable;

    @Autowired
    private RedisTemplate<String, String> redisTemplate;

    private static final ObjectMapper MAPPER = new ObjectMapper();
    @Override
    public boolean supports(MethodParameter methodParameter, Class aClass) {
        //开关处于开启状态,是get请求,包含了@cache注解
        return enable&& methodParameter.hasMethodAnnotation(GetMapping.class)&&methodParameter.hasMethodAnnotation(Cache.class);

    }

    @Override
    public Object beforeBodyWrite(Object body, MethodParameter returnType, MediaType selectedContentType, Class selectedConverterType,
                                  ServerHttpRequest request, ServerHttpResponse response) {
       if (null==body){
           return null;
       }

        try {
            String redisValue = null;
            if (body instanceof String){
                redisValue=(String)body;
            }else {
                redisValue=MAPPER.writeValueAsString(body);
            }

            String redisKey=RedisCacheInterceptor.createRediskey(((ServletServerHttpRequest) request).getServletRequest());
            Cache cache=returnType.getMethodAnnotation(Cache.class);
            //缓存的时间单位是秒
            this.redisTemplate.opsForValue().set(redisKey,redisValue,Long.valueOf(cache.time()),TimeUnit.SECONDS);
        } catch (JsonProcessingException e) {
            e.printStackTrace();
        }
        return body;
    }
}
